Stock-Based Compensation - Summary of Status of Stock Option Activity (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term	5 years 6 months 15 days
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Beginning Balance, Number of Shares	3,607	3,474	3,600
Granted, Number of Shares	659	559	529
Exercised, Number of Shares	(168)	(251)	(642)
Cancelled, Number of Shares	(131)	(175)	(13)
Ending Balance, Number of Shares	3,967	3,607	3,474
Vested and Expected to Vest, Number of Shares	3,827
Exercisable, Number of Shares	2,657
Available for future Grant, Number of Shares	1,434
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Rollforward]
Beginning balance, weighted average exercise price per share	$ 16.37	$ 14.74	$ 13.15
Granted, weighted average exercise price per share	23.15	26.63	22.36
Exercised, weighted average exercise price per share	12.30	13.67	12.16
Cancelled, weighted average exercise price per share	23.41	20.63	10.61
Ending balance, weighted average exercise price per share	17.44	$ 16.37	$ 14.74
Vested and expected to vest, weighted average exercise price per share	17.20
Exercisable, weighted average exercise price per share	$ 14.37
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Vested and Expected to Vest, Weighted Average Remaining Contractual Term	5 years 6 months 8 days
Exercisable, Weighted Average Remaining Contractual Term	4 years 1 month 28 days
Aggregate intrinsic value	$ 19,225
Vested and Expected to Vest, Aggregate Intrinsic Value	19,192
Exercisable, Aggregate Intrinsic Value	$ 18,503